Lieutenant M'Ress was a Caitian Starfleet operations division officer who served aboard the USS Enterprise under Captain James T. Kirk during the final two years of his five-year mission.

M'Ress' primary role on the Enterprise was that of the relief communications officer, a role she fulfilled in the absence of Lieutenant Uhura. Her duties included activating intership and intraship communications, as well as the activation of any alert signals ordered by the captain.